The families of nine of the 26 people killed and a teacher wounded two years ago at the Sandy Hook Elementary School filed a lawsuit Monday against the manufacturer, distributor and seller of the rifle used in the shooting.

Chief Engineer Robert Puciloski, who appeared at the National Transportation Safety Board hearing in Washington, D.C., said the railroad is “behind in several areas,” including a five-year schedule of cyclical maintenance that had not been conducted in the area of the Bridgeport derailment since 2005.